Flashcards: Blood Supply of the Brain and Spinal Cord — 61 cards

Which arteries supply the brain and form the circle of Willis?

Two internal carotid and two vertebral arteries supply the brain and form the circle of Willis.

What is the circle of Willis?

An arterial anastomotic ring at the brain's base in the interpeduncular fossa.

Which arteries are included in the circle of Willis?

Anterior communicating, anterior cerebral, internal carotid, posterior communicating, posterior cerebral, and basilar arteries.

What does the circle of Willis allow regarding blood flow?

It allows blood from internal carotid or vertebral arteries to reach either cerebral hemisphere.

What do cortical and central branches of the circle of Willis supply?

They supply the brain substance.

Are variations in the arteries of the circle of Willis common?

Yes, variations in artery sizes are common.

Which arteries in the circle of Willis may be absent?

One or both posterior communicating arteries may be absent.

Where does the internal carotid artery begin?

At the common carotid bifurcation.

Through which canal does the internal carotid artery enter the skull?

The carotid canal.

Into which arteries does the internal carotid artery divide?

The anterior and middle cerebral arteries.

What is the carotid sinus?

A localized dilatation at the origin of the internal carotid artery.

Where is the carotid sinus usually located?

At the common carotid bifurcation.

Where does the internal carotid artery emerge from the cavernous sinus?

On the medial side of the anterior clinoid process.

Before entering which space does the internal carotid artery pierce the dura and arachnoid?

The subarachnoid space.

Where does the ophthalmic artery arise from?

From the internal carotid artery as it emerges from the cavernous sinus.

Through which canal does the ophthalmic artery enter the orbit?

The optic canal.

Where does the posterior communicating artery arise?

Near the terminal bifurcation of the internal carotid artery.

Which artery does the posterior communicating artery join?

The posterior cerebral artery.

Where does the choroidal artery end?

In the choroid plexus of the inferior horn of the lateral ventricle.

What is the smaller terminal branch of the internal carotid artery?

The anterior cerebral artery.

Which area does the anterior cerebral artery supply?

The medial cerebral cortex, including the leg area of the precentral gyrus.

What is the largest branch of the internal carotid artery?

The middle cerebral artery.

From which artery does the vertebral artery arise?

The first part of the subclavian artery.

Through which vertebrae's transverse foramina does the vertebral artery pass?

The upper six cervical vertebrae.

Where do the vertebral arteries join to form the basilar artery?

At the lower border of the pons.

Which is the largest branch of the vertebral artery?

The posterior inferior cerebellar artery.

What areas does the posterior inferior cerebellar artery supply?

The inferior cerebellum, medulla oblongata, and fourth ventricle choroid plexus.

How is the anterior spinal artery formed?

By a contributory branch from each vertebral artery.

Where does the anterior spinal artery descend?

On the anterior surface of the medulla and spinal cord.

Into which arteries does the basilar artery divide at the upper border of the pons?

The two posterior cerebral arteries.

Which nerves does the labyrinthine artery accompany through the internal acoustic meatus?

The facial and vestibulocochlear nerves.

From which artery does the labyrinthine artery often arise?

The anterior inferior cerebellar artery.

Which parts does the anterior inferior cerebellar artery supply?

The anterior and inferior parts of the cerebellum.

Which brainstem areas receive branches from the anterior inferior cerebellar artery?

The pons and upper medulla oblongata.

What areas does the superior cerebellar artery supply?

The superior cerebellum, pons, pineal gland, and superior medullary velum.

Which lobe areas does the posterior cerebral artery supply?

The inferolateral and medial temporal lobe, and the lateral and medial occipital lobe.

What important cortex does the posterior cerebral artery supply?

The visual cortex.

Which central structures receive branches from the posterior cerebral artery?

Parts of the thalamus, lentiform nucleus, midbrain, pineal gland, medial geniculate bodies, and choroid plexuses of the lateral and third ventricles.

Which arteries mainly supply the corpus striatum and internal capsule?

Medial and lateral striate branches of the middle cerebral artery.

Which artery provides remaining supply to the corpus striatum and internal capsule?

Central branches of the anterior cerebral artery.

Which arteries mainly supply the thalamus?

Branches of the posterior communicating, basilar, and posterior cerebral arteries.

Which arteries supply the midbrain?

Posterior cerebral, superior cerebellar, and basilar arteries.

Which arteries supply the pons?

Basilar and anterior, inferior, and superior cerebellar arteries.

Which arteries supply the medulla oblongata?

Vertebral, anterior and posterior spinal, posterior inferior cerebellar, and basilar arteries.

Which arteries supply the cerebellum?

Superior cerebellar, anterior inferior cerebellar, and posterior inferior cerebellar arteries.

What type of walls do cerebral veins have?

They have very thin walls without muscular tissue or valves.

Where do cerebral veins emerge from the brain?

They emerge into the subarachnoid space.

Into which structures do cerebral veins drain?

They drain through the arachnoid and meningeal dura into cranial venous sinuses.

Which sinus do superior cerebral veins drain into?

They drain into the superior sagittal sinus.

Where does the superficial middle cerebral vein drain?

It drains the lateral surface into the cavernous sinus.

What veins form the basal vein?

The deep middle cerebral vein joins the anterior cerebral and striate veins to form the basal vein.

What veins unite to form the internal cerebral veins?

The thalamostriate and choroid veins unite at the interventricular foramen.

Into which sinus does the great cerebral vein drain?

It drains into the straight sinus.

From which arteries do posterior spinal arteries arise?

They arise from vertebral or posterior inferior cerebellar arteries.

Which part of the spinal cord do posterior spinal arteries supply?

They supply the posterior third of the spinal cord.

Which part of the spinal cord does the anterior spinal artery supply?

It supplies the anterior two-thirds of the spinal cord.

In which spinal segments are posterior spinal arteries small?

They are small in the upper three thoracic segments.

What can blockage of segmental or radicular arteries in upper thoracic segments cause?

It can cause ischemia.

In which spinal segments is the anterior spinal artery small?

It is small in the fourth thoracic and first lumbar segments.

From which arteries do segmental spinal arteries arise?

They arise from deep cervical, intercostal, and lumbar arteries.

What is the origin and significance of the artery of Adamkiewicz?

It arises from the aorta at lower thoracic and upper lumbar levels, enters from the left side, and supplies the lower two-thirds of the spinal cord.